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《wavelet transform analysis of acoustic emission generated during friction stir welding of 6061 aluminum外語(yǔ)英文電子書(shū)》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在教育資源-天天文庫(kù)。
1、Availableonlineatwww.sciencedirect.comSC!ENC2@DIRECTBMACHrNETOOLS&MANUFACTUREOe5lGN.RESE.&JICHANDAPPUt.lnQNPergamonfoccmationalJournalofMachine'Tools&Manufacrure43(2003)1383-1390VVavelettransformanalysisofacousticemissioninmonitoringfrictionstirweldingof6061aluminumChangmingChen,RadovanKovacevic
2、*,DraganaJandgricResearchCenterforAdvancedManufacturing,DepamnentofMechanicalEngineering,SouthernMethodistUniversiry,1500InrernationalParkway,Suire100,Richardson,TX75081,USAReceived4February2003;receivedinrevisedform28April2003;accepted7May2003AbstractInthispaper,acousticemission(AE)signalsarede
3、tectedandpreliminarilyanalyzedinordertoinvestigatethepossibilityofapplyingtheAEtechniqueforthein-processmonitoringofanentirefriction-stir-welding(FSW)process.ExperirnemaJtestsarecarriedourusingahigh-speedrotatingtooltraversingontwo,butted6061aluminumalloyplateswiththreeequallyspacedgapsmadeoftwo
4、notchesalignedalongthebuttingjointoftheparts.Thewavelettransform(WT)isusedtodecomposetheAEsignalintovariousdiscreteseriesofsequencesoverdifferentfrequencybands.Therearesignificantsuddenchangesinthebandenergya(themomentwhentheprobepenetratesintoandpullsouroftheweldjoint,aswellaswhentheshouldermak
5、escontactwithordetachesfromtheplates.Thebandenergyvariationduringthetraversingofthetoolover.thedefectedregionreflectstheexistence,location,andsizeofthewelddefects.Athree-dimensionalrepresentationofbandenergyvstimeandscalegivesvaluableinfor?mationonthepotentialwelddefectsduringfrictionstirwelding
6、.Coupledwithacontourmapping,therepresentationcanbeeffectivelyutilizedformonitoringthetransientweldingstateandquicklyidentifyinggapdefects.?2003ElsevierLtd.Allrightsrese~ed.Keywords:Acousticemission;Waveletanalysis;Frictionstirwelding;Processmonitoring;Welddefects'.1.'"1.Introductionwhichprovides
7、foramoreflexibleautomationinmanu?facturing[3].Friction-stir-welding(FSW)isasolid-statematerialAEmonitoringisoneofthemostsensitivetechniquesjoiningmethodresultinginalow-levelofdeformationthatisusefulforreal-timedetectionofcra
